From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0EF1BC43381 for ; Wed, 27 Mar 2019 18:08:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CB9572063F for ; Wed, 27 Mar 2019 18:08:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553710082; bh=PB82dimxUV0AIAOicB9oJW7kARm/9ChLH+QTTPwdbCY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=N2+brwu9o6LlLGvt6AdyaEgWbHj+7toaKpDNVmKNjioBYlvya99TdEQwy8U/+driG kXz15/TIStYdrTDHwtB8EJoFQm+l9ZdmxdnotSpDNFSmz5XFP5XIeOZTl8gQ4OobMr LxY7HxWsQwAqtgnpZUy+WuE+4vLv1HbaucpSVKTc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388287AbfC0SIB (ORCPT ); Wed, 27 Mar 2019 14:08:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:49798 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733293AbfC0SHw (ORCPT ); Wed, 27 Mar 2019 14:07:52 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C0D232063F; Wed, 27 Mar 2019 18:07:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553710071; bh=PB82dimxUV0AIAOicB9oJW7kARm/9ChLH+QTTPwdbCY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dQJJDdoHeUYPvNLDdj/W0LF9lGl5ZxZlSK4soUN1Q1awVVKbWMT+3Z2c/QqwG5q9F yLdowINZX9DEzMQBd4IHhDiLpRpMd+dL40n6Jfj3YaX1dUU4u9idJEc7mPFDnXVmaI oiD6FojjJy+6u0e4/q1Zd52AvEFRVQm74LoQArBc= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Hidetoshi Seto , Peter Zijlstra , Linus Torvalds , Masayoshi Mizuma , Mike Galbraith , Thomas Gleixner , Ingo Molnar , Sasha Levin Subject: [PATCH AUTOSEL 5.0 184/262] sched/debug: Initialize sd_sysctl_cpus if !CONFIG_CPUMASK_OFFSTACK Date: Wed, 27 Mar 2019 14:00:39 -0400 Message-Id: <20190327180158.10245-184-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190327180158.10245-1-sashal@kernel.org> References: <20190327180158.10245-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Hidetoshi Seto [ Upstream commit 1ca4fa3ab604734e38e2a3000c9abf788512ffa7 ] register_sched_domain_sysctl() copies the cpu_possible_mask into sd_sysctl_cpus, but only if sd_sysctl_cpus hasn't already been allocated (ie, CONFIG_CPUMASK_OFFSTACK is set). However, when CONFIG_CPUMASK_OFFSTACK is not set, sd_sysctl_cpus is left uninitialized (all zeroes) and the kernel may fail to initialize sched_domain sysctl entries for all possible CPUs. This is visible to the user if the kernel is booted with maxcpus=n, or if ACPI tables have been modified to leave CPUs offline, and then checking for missing /proc/sys/kernel/sched_domain/cpu* entries. Fix this by separating the allocation and initialization, and adding a flag to initialize the possible CPU entries while system booting only. Tested-by: Syuuichirou Ishii Tested-by: Tarumizu, Kohei Signed-off-by: Hidetoshi Seto Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Masayoshi Mizuma Acked-by: Joe Lawrence Cc: Linus Torvalds Cc: Masayoshi Mizuma Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/20190129151245.5073-1-msys.mizuma@gmail.com Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin --- kernel/sched/debug.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index de3de997e245..8039d62ae36e 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -315,6 +315,7 @@ void register_sched_domain_sysctl(void) { static struct ctl_table *cpu_entries; static struct ctl_table **cpu_idx; + static bool init_done = false; char buf[32]; int i; @@ -344,7 +345,10 @@ void register_sched_domain_sysctl(void) if (!cpumask_available(sd_sysctl_cpus)) { if (!alloc_cpumask_var(&sd_sysctl_cpus, GFP_KERNEL)) return; + } + if (!init_done) { + init_done = true; /* init to possible to not have holes in @cpu_entries */ cpumask_copy(sd_sysctl_cpus, cpu_possible_mask); } -- 2.19.1